1. Field of the Invention
The present invention relates to case loading machines, and in particular to a new method and apparatus for continuously stacking articles, cartons or packages for insertion into a case or box.
2. Description of the Prior Art
In the packaging industry, numerous different machines have been developed to accomplish the ever present tasks of erecting, filling, and closing containers ("cases" or "boxes") for goods. All of these tasks may be performed by a single machine, or they may be accomplished using a series of different machines, each machine dedicated to a different task. The machine of the present invention is designed to perform the task of continuously stacking cartons in a vertical orientation prior to insertion into open cases.
There are numerous automated stacking machines known in the prior art. Traditional carton stacking machines employ a lift at the end of a conveyor which brings incoming cartons. After a predetermined number of cartons are conveyed onto the lift, the conveyor stops as the lift first raises the stack of cartons up for delivery onto an upper catch plate, and then lowers back down into position to receive the next group of cartons. Machines which employ this method of operation are slow because of the inherent delay in the flow of cartons through the machine. This is because the lifting mechanism must raise and lower, stopping the incoming conveyor for considerable amounts of time.
Another continuous stacking apparatus is disclosed in U.S. Pat. No. 5,261,782. The complicated machine disclosed therein provides a pair of stacking plate assemblies which reciprocate in a stair-step fashion along the longitudinal incoming path of the product cartons. However, this inefficient and large machine requires countless moving parts and considerable space to perform the stacking operation.
It is therefore desirable to provide a compact, simple machine and method for continuously stacking cartons in a vertical orientation for insertion into cases.